Assigxob to him



UNITED STATES PATENT OFFICE.

WILLIAM GRIFFITH, OF PITTSBURG, PENNSYLVANIA, ASSIGXOR TO HIM- SELF AND JAMES C. GRAY, OF SAME PLACE. I

PROCESS OF PURIFYING MOLTEN IRON.

SPECIFICATION forming part of Letters Patent No. 289,086, dated November 27, 1883.

' Application filed May 25,1883. (No specimens.)

To all whom it may concern:

Be it known that I, .VVILLIAM GRIFFITH, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvementin Processes for Purifying Molten Iron; and I do hereby declare the following to be a full, clear, and exactde scription thereof.

My invention relates to an improvement in the manufacture of iron and steel; and it consists in treating the molten met-al with nitrate of ammonia and sulphate manganese in order to refine it and to remove impurities there from. These chemicals may be added or in- 5 troduced into the molten metal after it has been run from the furnace into the ladle or mold, or they may be added to the metal in Bessemer converters,puddling, refining, openhearth, cupola, blast, and other furnaces.

I will now describe my invention, so that others skilled in the art may use the same. a WVhen the metal has been reduced to amolten state in thefurnace, nitrate of ammonia and sulphate manganeseequal parts of each are 5 added thereto. These chemicals unite with the impurities and rise to the surface with the slag, leaving the refined and purified metal free to be drawn from the furnace. In the puddling-furnace the chemicals should be added to the metal while it is still boiling and before it comes to nature.

In order that the chemicals may act properly, care should be taken to place them beneath the surface of the molten metal.

5 may be easily accomplished by inclosing them in thin metal cases or boxes.

Instead of introducing the nitrate of ammoni a and sulphate manganese into the furnace,

they may be placed in the ladle, mold, or Bes- 0 semer converter before the molten metal is poured therein.

This

The amount of nitrate of ammonia and sulphate manganese to be added to the metal depends upon the quality of the iron or steel and the amount of impurities, phosphorus, and other foreign substances contained therein; but for ordinary grades of metal forty-five ounces of nitrate of ammonia and a like quantity of sulphate manganese may be used with each ton of metal.

The advantages of my invention are that the phosphorus and other foreign substances are removed from the metal, and it is therefore tough and fibrous throughout, and a superior quality of manufactured iron or steel may be produced from an inferior quality of metal.

I am aware that nitrate of ammonia and salts of manganese have heretofore been used independently of each other andin conj unction each with various other chemicals in the preparation of physio for the purification of iron, 850., and do not herein claim the same; but I am not aware that the sulphate of manganese has heretofore been so employed, or that a compound consisting of only the two articles herein specified has been so used. Therefore,

Having thus described my invention, What I claim, and desire to secure by Letters Patent, 1s'

The process herein described of refining and purifying iron and steel, which consists in subjecting the molten metal to the action of a compound consisting of the two ingredients, nitrate of ammonia and sulphate of manganese,in substantially the proportions specified, as and for the purposes set forth.

In testimony whereof I here hereunto set my hand this 19th day of May, A. D. 1883.

IVILLIAM GRIFFITH.

Witnesses:

W. B. CoEWIN, J. K. BAKEWELL. 

